Tank



Patented June 23, 1936 PATENT OFFICE I TANK I Paul M. Kllellll, Baltimore, in, assignor to The Bartlett Hayward Company, Baltimore, Md., a

corporation of Maryland I Application November 7, 1933, Serial No. 697,033

' 1 Claim. (01. 220-1) This invention pertains to tanks or holders for fluids or liquids, and more particularly liquids which vaporize or gasify readily and, being at pressure greater than atmospheric, subject the tank in which they are stored to an uplifting action.

The structure of the tank of the present invention is such that it will withstand the pressureof the gas which may be given off by the stored liquid, and at thesame time will prevent the uplifting action above mentioned from distorting the tank structure. The uplifting forces which tend to give the bottom of the tank spherical configuration will be balanced by anchors in the earth or other support, so as to prevent undesired distortions of the structure, and to prevent these forces from being transmitted to the tank bottom.

Tanks of-the type herein referred to are of large capacity and the, problems presented are commensurate with those which are met in structures of a capacity approximating that of the large gas holders which are in commercial use.

The capacity of one tank embodying this invention was thirty thousand barrels, the tank body having a diameter of approximately sixty feet and a height of approximately ninety feet. This example is'given to indicate that the problems to be met are ofunusual scope and difler materially from thosemet in the design of small liquid containers. i

Broadly stated, the invention consists in'providing a rigid self-supporting tank structure without the usual rigid tank bottom, and providing in its stead a flexible membrane or bottom formed of thin light material which has to withstand very small stresses and, hence, can be made at very reduced cost.

The walls of the tank are securely anchored to theearth or other supporting structure, and these anchors absorb the stresses tending to lift the tank, which stresses would, in ordinary tank structures; be applied to the tank bottom when a volatile fluid or liquid'under a pressure head is introduced therein.

One tank embodying this invention is shown in the accompanying drawing, in which:-- a

Fig. l is a side elevation of a tank with the lower portion broken away to show the tank bottom;

Fig. 2 is a fragmentary vertical sectional view illustrating one manner of securing the tank body and bottom together and of anchoring the body to its support; and

Fig. 3 is a view similar to Fig. 2, showing a modified form of bottom construction.

Referring to the drawing, in which onestruc-l ture embodying this invention is illustrated, the

reference character 5 designates a cylindrical 5 shell made up of metal plates 1, secured together as by bolting, welding or riveting, or in any other suitable manner. The shell is then self-supporting, without the provision of a reinforcing frame. The cylindrical shell 5 merges gradually into a 10 hemispherical top or dome 6 designed to withstand internal pressures caused by liberated gases, and to afford the necessary resistance to distortion by the stresses exerted by such gases.

Closing the lower end of the shell or body 5 is 15 a membrane 8 of thin sheet material, preferably but not necessarily of metal and of a thickness considerably less than that of the shell 5, and resting directly on the earth E. While reference is made herein to the use of a metal for the mem- 20 brane 8,-it maybe made of other suitable, material. For example, the membrane may be of rubber, rubberized fabric, or a fabric such as canvas liquid -proofed with an agent which is insoluble both in the liquid to be stored and in wa- 26 -ter.which may be present in or below the tank.

In prior art constructions, it has been neces- ,sary inpractically all cases to provide a concrete or other base upon which the tank bottom rests,

but with the constructionshown herein and described, such a supporting base. be omitted. the earth Ebeingpreferablytamped before the membrane-8 is placed inposition,

In the form of the invention shown in Fig. 2,

an angle iron 9 extends around the lower inner edge of the shell 5 and is riveted to that shell at H, The horizontally extending flange. of this angle iron may be riveted to the membrane 8 to produce a liquid-tight joint. It will thus be clear that the flexible membrane 8 serves the, 40 purpose of sealing the shell 5 at the bottom, but rests directly upon the-earth and the parts are so arranged that when volatile liquid under a pressure head enters the tank, the membrane is subjected only to gravitational stress.

The shell 5 is anchored to the earth or other supporting structure by brackets l2 riveted to it and attached'to the earth by anchor rods l3 bolted thereto at suitable intervals. The rods", in the structure illustrated, are embedded 111,60 concrete, the body of concrete in this instance being shown as of approximately inverted Y shape in cross section, so as to' be capable of withstanding powerful forces tending to lift it upwardly. v

Also embe d in the concrete are other anchor rods 15, each having an enlarged head 15 extending beyond the body of the concrete and positioned so as to withstand any upward pull to which the rods l3 and I5 maybe subjected. 6

The rods I3 are bolted to the brackets l2 and are tightly secured thereto so that when gases are liberated withinthe tank and exert an uplifting action on the body of the tank. the upwardly acting stresses are transmitted from the shell 5 to the brackets l2, and hence to rods l3 and the associated anchor structures. These forces tending, to produce deformation and spherical configuration to the membrane 8 are absorbed by the anchor rods and the concrete structure in which they are buried. Consequently, these uplifting forces are borne entirely by the earth or' other base and the need for a flexible joint between the bottom 8 and the wall 5 is entirely eliminated.

The reference characters I9 and 2! designate liquidinlts and outlets which may be of any suitable form, and maybe conveniently located in accordance with conditions. All other ancillary structures, such as are commonly used with tanks of this character for providing access to the top of the tank and to the interior of the tank have been omitted, since they form no part oi the present invention.

The structure shown in Fig. 3 is similar to that of Fig. 2, except that the membranous bottom, here designated l'l, extends beyond the outer shell 5 and is attached thereto by the anchor rods l3 cooperating with an angle iron l8 placed outside of the shell 5 and secured thereto as by bolting, riveting or welding.

The function of the structure shown in Fig. 3 is similar to that already described in Fig. 2, it

being noted that all uplifting stresses applied to the shell 5 are transmitted directly to the anchor rods "and the associated structure buried in the earth.

It will be clear that the structure just described consists of a simple self-supporting body the contents of the tank, said tank being conand top with a thin flexible bottom which may rest directly on the earth.

The body alone is anchored to the earth, so that uplifting forces applied to the tank body are taken up by the earth and resist all tend- 5 ency of the bottom to be deformed. At the same time, the bottom is of thin construction and is capable of accommodating itself to any irregularities which are present in the space which it occupies, without damaging results to the tank 10 structure.

While the accompanying drawing shows the tank bottom resting directly upon the earth, and such a structure is preferred, it will be obvious that any suitable base capable of withstanding the weight of the super-structure may be employed where practicable, instead of placing the tank directly on the earth. However, the present invention makes direct application to the earth practicable whereprior art structures could never have done so.

What is claimed is:

A high capacity storage container for volatile liquids, comprising in combination a verticalwalled cylindrical body having a dome shaped top constructed to withstand internal vapor pressure; a fiat bottom resting directly on the earth and of a thickness not substantially more than sufflcient-to withstand the gravitational load of structed and proportioned so that its weight is less than the upwardly acting forces exerted upon it by the maximum permissible internal vapor pressure exerted by the volatilized matter in the tank; a direct non-yielding connection between the vertical tank wall and the bottom of the tank; and anchoring means connected to said vertical wall and to the earth for absorbing the upwardly acting stresses in excess of the weight of the tank, said means serving to relieve the 40 tank bottom of all upwardly acting stresses which tend to give the bottom a spherical configuration, whereby ,the thickness ofsaid bottom may be reduced to a minimum.

4 PAUL M. KUEHN. 5 

